That question makes me smile :)Nice little pic Red! You can make most brushes sharper by using your fingers and some spit… But not if they're too old and used; then they'll resist it. :(In order to get smoother lines you should make sure you don't have any excess drippy liquid on the brush and then drag it across the paper with a light even pressure until you get to the end of your line. -press just hard enough to get the width you desire.

To get thinner line, press softer.

For even thinner lines get a smaller diameter brush, but remember that smaller brushes hold less ink for each dip so you'll have to restart lines in the middle and risk drips and blots.

The way you've painted your figure shows you know how to hold a brush lightly, but that particular technique lends iself more to actual painting than inking, it's also good for detail work; but not very good for lines.